1. Field of the Invention
This invention relates to the field of electrical contacts used in electrical apparatus. More particularly, the invention relates to a self-cleaning electrical contact which prevents oxides, dirt and other undesirable substances from building up on the surface of the contact.
2. Description of Related Art
Electrical contacts are used in a wide variety of applications. One example is in a battery charger, where the electrical contact is electrically connected to a voltage source and is the point of contact between the voltage source and a battery pack. Electrical contacts for battery chargers, particularly those used in field operations, tend to be exposed to the outside environment for long periods of time. As a consequence, layers of oxides, dust, and dirt can build up on the surface of the contact. If the contacts are not cleaned regularly, or the contaminants are not otherwise removed regularly, they can build up to form a layer of insulation, providing a high resistance to current flow. The build up of oxides and debris often results in a poor or or ineffective contact between the electrical contact of the battery charger and the electrical contacts of the battery packs. This in turn causes a high percentage of ineffective charging of the battery packs. Since the battery packs are susceptible to poor charging, the performance of the entire system based on the battery packs is reduced. When the system relying on the battery pack is a mobile communications system such as a hand-held portable radio system, the need for reliable charging of the battery packs becomes an import performance issue.
Prior electrical contacts used in battery chargers for hand-held radios have used single point contacts. The contacts are prone to build up of oxides and dirt unless regularly cleaned. There has been a long-felt need for an electrical contact which resists the build up of oxides and dirt, and for an electrical contact which has a self-cleaning ability.
This invention solves that need by providing a novel and advantageous electrical contact which has self-wiping and self-cleaning characteristics, whereby the electrical contact is cleaned of oxides and dirt every time it is used. The electrical contact of this invention results in more reliable performance of the battery charger or other apparatus that uses the inventive electrical contact.
Accordingly, an object of the invention is to provide an electrical contact which has a self-cleaning ability to prevent undesirable oxides and dirt from building up. A related object of the invention is to ensure that a good, reliable electrical connection is made between the electrical apparatus using the inventive electrical contact.
Another object of the invention is to provide an improved battery charger arrangement whereby a battery pack is reliably charged using the inventive electrical contact due to the electrical contact's self-wiping and self-cleaning characteristics.